1. Field of the Invention
The present invention relates to a fuel injection valve.
2. Description of the Related Art
In order to inject fuel into a cylinder of an internal combustion engine, a fuel injection valve is used. The following type of fuel injection valve is provided. As shown in FIG. 12, the metering plate 3 is arranged in the front of the forward end portion of the needle 2 which is slidably provided in the valve body 1. Via the fuel passage 4 formed between the valve body 1 and the needle 2, fuel flowing between the lower face of the needle 2 and the upper face of the metering plate 3 is injected from the nozzle hole 5 formed on the metering plate 3. FIG. 13 is a top view of the metering plate 3, on which a plurality of nozzle holes 5 are equally formed. FIG. 14A is a top view showing a flow of fuel around one nozzle hole 5. FIG. 14B is a sectional side view of the flow of fuel around the nozzle hole 5. In this case, fuel is cylindrically injected, and what is called a liquid column spray is generated.
As disclosed in the official gazette of Japanese Unexamined Patent Publication No. 9-32695, there is provided a fuel injection valve in which the nozzle hole 5 is obliquely formed so as to suppress the generation of a liquid column spray.
However, the regulations regarding exhaust gases have been further strengthened recently. Accordingly, there is a possibility that the above fuel injection valve of the prior art will be insufficient to fulfil these regulations.
Accordingly, there is a demand for a fuel injection valve capable of atomizing excellently fuel.